Control of metallic appearance in automotive cast paint films

A coating process for controlling the metallic appearance of a cast automotive paint film so as to resemble the appearance of a spray painted metallic paint finish, the process comprising:

• casting a layer of a thermoplastic automotive paint coat onto a supporting surface, the paint coat comprising a polyvinylidene fluoride (PVDF) copolymer dispersed in a solvent-based solution of an acrylic resin to form a dispersion in which the PVDF copolymer has an average particle size between about 1 and about 35 microns, the dispersion containing from about 20% to 80% PVDF copolymer and from about 80% to about 20% acrylic resin, respectively, by weight of the total PVDF copolymer/acrylic solids contained in the dispersion;
• the paint coat further comprising a pigment uniformly dispersed in the PVDF copolymer/acrylic resin dispersion to provide coloration, and reflective flakes uniformly dispersed in said dispersion to impart to the finished paint film a metallic appearance;
• and
• drying the paint coat on the supporting surface to fuse the paint coat and thereby form a finished metallic automotive paint film;
• the paint coat being cast by a coating process in which the dispersed form of the PVDF copolymer particles in the acrylic solution disorients the reflective flakes to inhibit their parallel orientation such that the flake orientation in the finished paint film resembles the random distribution of a spray-painted metallic automotive paint coat of the same color, the finished paint film having a Travel Index substantially the same as the Travel Index for a fused spray-painted coat of the same color of metallic automotive paint when viewed at different viewing angles.

A process for controlling the metallic appearance of a metallic automotive paint film containing reflective flakes to achieve a random orientation of the reflective flakes, the process comprising:

• coating a layer of a thermoplastic and thermoformable pigment-containing metallic automotive paint coat onto a carrier;
• the paint coat comprising a dispersion of a polyvinylidene fluoride material in a solvent-based solution of an acrylic resin, the dispersed polyvinylidene fluoride material having a mean particle size distribution range from about 3 to about 11 microns and being uniformly dispersed in the solution of acrylic resin, the paint coat further comprising a pigment uniformly dispersed in the paint coat to provide coloration, and reflective flakes uniformly dispersed in the paint coat to impart to the paint film a metallic appearance;
• and
• drying the paint coat to fuse the paint coat and thereby form a finished metallic automotive paint film in which the parallel orientation of the reflective flakes to one another is inhibited such that the flake orientation of the finished paint film provides a randomly oriented distribution of the reflective flakes.